An image sensor is a part for photographing images in a device such as a portable phone camera or a digital still camera (DSC). An image sensor can be classified as a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor, depending on the manufacturing process and the method of using the same.
A color photographing part for a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor includes color filters, each having additive mixing primary color filter segments of red, green, and blue, and the colors are separated.
A recent color filter embodied in the color photographing part has a pattern size of 2 μm or less, which is 1/100th to 1/200th of the pattern size of a conventional color filter pattern for LCDs. Accordingly, increased resolution and decreased pattern residues are important factors for determining the performance of a device.
It is believed that the kind and composition ratio of a photoinitiator, a monomer, and a binder and the pigment dispersion solution determine whether the resolution is increased and the pattern residues are decreased. Furthermore, in order to provide a fine pattern, the pigment dispersion solution should be prepared to have a small particle diameter and a composition that does not leave pattern residues when developing an image. In order to decrease the dispersing particle diameter of the pigment dispersion solution, the pigment should have a small primary particle diameter, and the kind and amount of a dispersing agent should be considered.
Recently, a photosensitive resin composition including a dye capable of dissolving in an organic solvent has been developed in order to overcome the limitations of pigments. Such a dye which is capable of dissolving in an organic solvent can reduce residues and improve resolution and provide higher luminance and color contrast than a color photosensitive resin composition for a display color filter. However, conventional dyes have limitations, such as poor heat- and light-resistance.